Some global warming (GW) activists, such as Quiggin & Gore, like to claim that there is no ongoing controversy regarding global warming and no serious debate between the mainstream and the skeptics. This has sparked a debate about whether there is a debate.
One part of the debate (used by Gore in his movie) comes from the study by Naomi Oreskes that claimed 0/928 abstracts for academic papers on global warming doubted the mainstream position and that 75% back the consensus view. Benny Peiser tried the same trick and found different results with less than 2% explicitly backing the consensus*, some showing skepticism and most giving no opinion (and 24 not even offering abstracts). Both papers have been criticised and both authors have admitted mistakes. Peiser continues to insist that Oreskes is wrong to claim unanimous support of the consensus view and cites numerous examples to the contrary.
Pieser freely admits that the skeptical view is a small minority, but he continues to insist that “despite all claims to the contrary, there is a small community of sceptical researchers that remain extremely active. Hardly a week goes by without a new research paper that questions part or even some basics of climate change theory” and he cites a recent example.
In addition, many skeptics accept elements of the consensus position but are skeptical of catastrophy or the need for action.
Another part of this debate is the skeptical Oregon petition, signed by 19,500 people, including 17,100 scientists (2/3rds with advanced degrees) and 2,660 of those trained in physics, geophysics, climatology, meteorology, oceanography, or environmental science.
The petition has been criticised for lack of transparency and lack of independent verification, though the organisers claim that 17,800 (and 95% of PhD holders) have been independently checked. Another criticism is that the document attached to the petition uses data that is now out of date.
In 2005, Scientific America checked with 21 PhD signaturies** and found that 11 still agreed, 6 had changed their mind, 1 had died and 3 couldn’t remember the petition. They estimated that only about 200 PhD educated climate researchers would still support the petition.
Others have criticised the petition for including fake names. Petition organisers have removed some prank names (Gerry Halliwell) but retain some apparently prank names (Perry Mason) as they have been identified as real and qualified scientists (Perry Mason has a chemistry PhD).
Some inappropriate names may well still exist among the un-checked names. Some people may well have since died or changed their minds. However, even the Scientific America estimate (with only climate scientists) still shows a small but significant skeptical group.
Peiser’s work and the Oregon petition are imperfect, but that doesn’t mean they are worthless. Despite their problems they do indicate that the GW consensus isn’t absolute, skeptics are alive and well, and the debate goes on.
UPDATE 6/12/06: I also noticed there is another survey done in 2003 by Prof Dennis Bray among about 500 climate researchers showing that 55% agreed the global warming is mostly man-made, 14% were unsure and 29% had doubts. This showed a small shift towards the consensus view since the previous survey done in 1996. There are questions about how the survey was conducted (possible self-selection bias) but it is difficult to believe that every non-consensus answer is a fraud.
UPDATE 7/12/06: Another interesting read by Michael Duffy which discusses the very real existence of skeptics.
* Note that one reason for the difference is that Peiser only reports abstracts that explicitly support the consensus position.
** Scientific America actually searched for 30 people, but could not find 4 and 5 didn’t respond to their inquiries, leaving a sample size of 21.